Pathology Of The Nervous System

The nervous system is the most challenging organ system to thoroughly assess in toxicity studies. It is anatomically complex, changes may occur within limited time frames, it may require special processing and special staining/immunohistochemistry, and it is prone to artifacts and spontaneous, background changes. Although there are regulatory guidelines for general examination of the nervous system, they typically do not offer sufficient guidance for detailed neurotoxicity studies. This chapter provides recommendations for general and detailed neurotoxicity studies including recommendations for sampling, special processing, embedding and staining, study design, and fixation methods to limit artifact formation. In addition, it explains potential changes that commonly occur in both the central and peripheral portions of the nervous system of laboratory animal species and introduces the terms that are commonly used to diagnose these changes in neurotoxicity pathology reports.

ence.For example, in persons of a nervous temperament, sudden and overwhelming intelligence will sometimes temporarily stop the heart's action.Physical impressions, again, such as crushing a part ot the brain or spinal marrow, will temporarily palsy the heart; an experiment the Wore conclusive, that the heart's action will continue undisturbed during the entire removal of the brain and spinal marrow, if the abstraction of these parts be made with gentleness.Is it surprising that lesion of the brain, which can Palsy the heart, the action of which is not derived from the nervous system, should throw palsy upon the voluntary muscles, that in so many ways are ha- bitually influenced through it?Such a force of depression, similar in kind, al- though much less in degree, mental affections alone have the direct power of temporarily producing; the ' genua labant, tremor occupat artus/ the weakness of terror, is probably an instance of imperfect or temporary palsy so produced.

Upon these and other grounds, which will be resently mentioned, it appears reasonable to believe that a lesion of the brain is ca able of originating a depressing force, which can strike with palsy the organs in the cord from which the nerves arise ; or that palsy from cerebral disease is not caused by the interruption of an accustomed stimulus, but by the production of a nevv and withering 'nfluence, transmitted from thence to the origins of the nerves." 200.

It is obvious that the chief merit of any explanation of this sort is its

Nearness.The fact that it affects to solve is admitted?thequomodo is the P?int at issue.

If obscurity attends the solution of that, it leaves us where !t found us, or plunges us deeper in the dark.

Unless Mr. Mayo applies the term shock in its ordinary sense; it conveys of course no clear idea.

We presu e, then, that in such a sense it is era- ployed, and that Mr. Mayo's theory supposes the brain capable of originating a sudden, violent, and injurious impression upon parts, which it may or may not habitually influence.

But the very term shock does not imply a continuous action, while the Pa]sy occasioned by lesion of the brain is as constant as its cause.A small eftusion of blood occurs in a cerebral hemisphere?hemiplegia instantly re- sults.Gradually the blood is altered, absorbed?gradually the hemiple- gia ceases.Does this look like a shock?" a withering influence" ?Is it consistent with what we know of the economy, to s ppose that an organ is gifted with the strange and monstrous function, of originating a new action only for mischief when itself is altered ?

Look at the plain case.The brain is sound?voluntarymotion and sen- sation are perfect.The brain is altered?sen e and voluntary motion are ^paired.The brain recovers?senseand voluntary motion are restored.

Purely the obvious rationale would be?voluntary motion and ensation do- [Oct. 1 pend on the integrity of the brain, and are modified by its alterations.We have just the same evidence of th connexion of the intellect with the cere- brum?of the senses with it.The portion of brain with which the optic nerve is in relation is destroyed?so is sight; or is partially injured?and vision is perverted.Mr. Mayo's reasoning- ould go to the position, that si -ht is lost, not because the sense was the result of the right action of the brain, but because the brain transmitted a shock to the optic nerve.We crush a portion of the brain, and the individual loses his memory or becomes an idiot.All believe that this is because memory and intellect depend upon the brain, and are destroyed with its destruction.The evidence is just the same as in the case of hemiplegia.Mr. Mayo's explanation is as applicable to the one as to the other.

Mr. Mayo observes that analogy is for him, and he cites one.Strange that that analogy is evidence against him.The brain, he observes, receives a shock through the medium of the intelligence.The voluntary muscles are affected, and even the heart, confessedly not under the immediate influence of the brain, falters in its action.Supposing this the evidence of shock in one case, its absence should be deemed evidence against shock in another.Now, in the instance of hemiplegia, the heart is confessedly not affected.

The patient has lost the use of one side of his body, yet his heart continues beating with nearly the same rhythm as ever.A pretty plain hint that those functions only are interfered with, which the brain has the office of regu- lating.

The whole reasoning is lax, and many questions are involved that cannot be so summarily settled.Mr. Mayo, for example, asserts, without any qua- lification, that the action of the heart is not derived from the nervous sys- tem.

Nay, he esteems this so clear a matter, that it is even placed in the middle of a sentence.If, by nervous system, are merely meant the ence- phalon and spinal marrow, no doubt the heart is very independent of them; but, if we include also the ganglionic system of nerves, that independence is not quite so clear.

The remainder of the chapter on palsy is occupied with the attempt to an- swer four distinct questions.We may be sure that those questions are in- tricate, or they would not be separately treated?that they are important, or they would not be put prominently forward.Let us examine them.

1. How does it happen that a lesion of one side of the brain invariably produces palsy of the opposite side of the body ?The

is no
a student of two years' standing

ho d
es not know that this is so.

There is not one in ten who can tell why.The explanation is ana- tomical and so far precise, and the chief admission necessary to give it weight is this, that the nervous influence moves in the direction of the fila- ments of the nervous matter?anadmission which the most resolute stickler for facts may gulp.

" Anatomists therefore look with curious interest to the construction of the enkephalon, in the expectation of discovering some transposition or crossing over of nervous f laments from one side to the other, through which the crossing of the depressing influence, or palsy-shock, may be supposed to be conveyed.

After the most careful research, it appears that such a transposition or decus- sation of nervous threads is to be found in the medulla oblongata alone.Where the medulla oblongata joins the spinal marrow, the anterior pyramids throw their fibres downwards, in oblique decussation, each to the opposite side, in such a manner that the right anterior pyramid plunges into the centre of the left half of the spinal marrow, while the fibres of the left anterior pyramid plunge into the right half of the cord."

Mr. Mayo concurs, as most physiologists do, with those who think that these decussating filaments are the channels by which the palsying" influence is conveyed from one hemisphere to the opposite side of the body.He does so upon several grounds; first, because these decussating fasciculi are the only ones which have been discovered in the enkephalon ; secondly, because the position of these decussating fasciculi is exactly that which ex- periment and observation lead us to expect to be the place of the transposition of palsy ; thirdly, because all the phenomena of hemiplegia, from lesion of the opposite side of the brain, may be explained upon this supposition; fourthly, because even the remarkable cases in which partial hemiplegia of the opposite side is combined with partial palsy on the side of the cerebral lesion, admit of a perfect explanation on the same hy othesis.

The chief facts in its favour are to be found in a paper by Dr. Yelloly.

They have been glanced at by Dr. Marshall Hall in the paragraph that we have quoted from him.But they merit more special mention.1.Sir Astley Cooper divided in a dog the right half of the spinal marrow, at the interval between the occiput and atlas : the dog became palsied on the injured side.It may be inferred from this experiment, that the seat of the transmission of palsy is to be found above the atlas.

2. Dr. Yelloly describes a case of hemiplegia, which had affected the Itft side of the body.On dissection, a tumor, of the size of a filbert, ^as found to have been imbedded in and to have made pressure on the right side of the muscular protuberance.

Thus while his case seems to prove that the seat of the transit of palsy ls behind or below the pons, the experiment of Sir Astley Cooper establishes that it is above the spinal cord.The intermediate somewhere must be in the medulla obl ngata or its junction with the spinal cord?where the decus- sation of the nervous filaments has been discovered.The evidence appears to be very satisfactory.

But other phenomena require consideration.The transmission of palsy across the body seems to be accounted for.Will the same explanation dually serve the ases which follow ?" Will," asks Mr. Mayo, " in the first place, the course of the decussating fibres account for the production of numbness, or anaesthesia, as well as of Muscular palsy ; for the former, although not a constant attendant of the latter, ^ay be combined with it, or eve exist without it ?Upon this question no one, ^*ho has well examined the anatomy of these parts, will entertain a doubt.Th decussating fasciculi of the anterior pyramid, on plunging into the opposite col mn of the spinal marrow, strike into its centre, and implicate themselves Nearly as much with the posterior as with the anterior fasciculi; that is to say, 'With the sentient as well as with the voluntary portions of the cord : so that the fonder is, not that anaesthesia should be produced through their agency, but that [Oct. 1 for the fibres of the pyramids, which are continuous upwards, on the one hand, with the cerebral hemispheres of the same side, or with the seat of lesion on the other hand, are continued downwards into the upper part and centre of that tract, from which the whole of the spinal nerves are d rived.But how is it possible to account for palsy of the opposite side of the face through the same channel, for palsy of the opposite side of the tongue, and of the opposite facial and auditory nerves?These phenomena may, I think, be thus explained: Where the decus- sating fasciculi of the anterior pyramid plunge into the opposite half of the spinal marrow, they are implicated, in a wonderful closeness of intertexture, with fibres, which, in their upward course, bend towards the places of origin of t e ninth and seventh, and of the eighth and fifth of the palsied side.May it not be supposed that this interlacement maybe a sufficient means of communicating the palsying influence to the ascending fibres, which are in close relation to the affected cerebral nerves?Thus, the palsy-stroke transmitted to the junction of the spinal cord and medulla oblongata, might spread its influence in either di- rection separately, or in both together, according to laws which may possibly be hereafter rigorously determined ; sometimes striking the body alone with palsy, sometimes the face, sometimes both ; sometimes palsying speech, sometimes deglutition, sometimes hearing." 203.That it is by the implication of the fibres of the pyramid with other fibres in connexion with the ninth and seventh is probable.But we feel here the contrast between conjecture and the comparative certainty that the cumula- tive evidence in the former case afforded us.All is doubt, an we catch at the solution because it is the best, not because it is a good one.Much of the plausibility of Mr. Mayo's argument, owes its force to the employment of language symbolical of actions which probably do not exist.In a mesh of fibres the mind readily-seizes the idea of a shock diffused amongst them.But more exact reasoning doubts the fact and disregards the metaphor.

Such fact and metaphor are still m re unsparingly employed in the passage we proceed to introduce.The reader might suppose that the cerebral influence, was dealing its blows like a hammer in a smithy, and the pith of the argument is the physical, and probably the false analogy.

" But t e fifth nerve, why is it so rarely affected in hemiplegia ?and the orbital nerves, why do they so frequently escape the palsying influence?These phenomena, it will be .evident,are highly consistent with the supposition that the palsying force strikes exactly at the point where the decussating fibres of the an- terior pyramids terminate.Supposing the paralysing impression to be received on this part, its force upwards should be weakened in proportion to the distance of each cerebral nerve from that part.But the fifth lies further off than the seventh, the third than the fifth; and something in that proportion is the infre- quency of the palsy of these nerves in hemiplegia." 203.All this is so very and so objectionably vague, that Mr. Mayo will do well to cancel it hereafter.

For the present, however, he is not content with a modicum of a hypothesis, but manfully carries it out.The hammer still rings in the theoretical forge, and the physiological smith seems to think that " in for a penny, in for a pound" is a canon in philosophy.For he applies the same description of explanation to the occurrence of hemiplegia from lesion of one hemisphere of the cerebellum.The pons consists in great part of filaments which issue from each he isphere of the cerebellum.Th se filaments meeting the filaments of the anterior pyramid of the same side, give them a shock, which is communicated to the same part as is paralysed in the cerebral lesion.

To explain the coincidence of hemiplegia on one side, with partial palsy on the other, Mr. Mayo relates a case in which these circumstances occurred.The patient recovered in a great degree; no examination after death could take place.The facts being uncertain, the case explains nothing, and al- though Mr. Mayo's conjectures are ingenious, they remain conjectures.We Way, therefore, ask our readers and ourselves the second question, with the hope that it may be answered more satisfactorily than the first has been.

2. What reason can be assigned for the facts, that in general hemiplegia from cerebral lesion, the palsy of the leg is less complete, and capable of being more quick ly recovered from, than the palsy of the arm ?Any body who had heard of the shock wliich has been eloquently intro- duced by Mr. Mayo, would at once comprehend the necessity of applying it to the answering of the interrogatory.The distance of the toes from the brain being greater than that of the fingers, the shock is of course transmit- ted to the former with less violence, and does less mischief when it reaches them.Nothing could be more physically obvious.

But those who doubted the occurrence of a shock before, are not likely to be more satisfied now.If they believed that paralysis was interruption of the influence of the cerebrum, they would conclude that that influence, being most decided in the parts more immediately connected with the cerebrum, its loss would be there more sensibly pronounced.We must remember that, how ver the encephalon may preside over some of the functions of the spinal marrow, it plays also a part of its own, and its operations are least dependent

?n the brain the farther it is removed from it.

3. Why, in a slow attack of palsy, are the muscular weakness and the numbness first felt in the extr mity of the affected limb ?Why in the hand before the fore-arm?in the fore-arm before the upper arm ?

" In this instance it may be presumed that a diminution of the usual quantity ?f stimulus or energy, tra smitted along the nerves from the organs in which they rise, is the cause of the effect observed.A part of, the cord is smitten with imperfect palsy-stroke; it cannot energize as before, or throw along the ner es ^'hich arise from it the usual quantity of nervous force.Upon this supposition it would follow, that the defect of stimulus should first become sensible at the extremity of a limb.The weakened segment of the cord might be expected to he unable to throw out energy enough to fill a long nerve, while it yet might supply with adequate force of stimulation the shorter nerves of the portion of the limb nearer the trunk.The fact presents a remarkable contrast with the !ast class of facts adverted to, and shews at all events that the two are not refe- rable to one principle.In slow hemiplegia, the arm is struck before the leg ; hut the hand is struck before the arm."207.

It is well known that sensations, having their source in the course of a nerve, are frequently referred to its extremity.But more tha this.Pres- sure on a nerve sufficient to occasion some interruption to its functions, or lesion of a nerve, will induce paralysis at its extremity, and its extremity only.We will mention an example of this.A girl had the head of the humerus excised.Abscesses and thickening occurred about the shoulder.

Suddenly the extremi y of the little finger, and of the ulnar side of the ring- finger, became insensible to ordinary s imulants.It was not the whole of those fingers, but their extremities only, that were thus affected.This loss of sensation endured for a long time, but gradually, we believe, subsided.Now here was an instance in which, no doubt, the ulnar nerve was impli-[Oct.J cated near the shoulder in disease.Yet the paralysis was only felt at its very extremity.This appears to be an instance of the same sort, as the com- mencement of hemiplegia in the distal end of a limb.Probably the obvious explanation of Mr. Mayo is correct?it is the most plausible one that presents itself.The influence derived from the nervous centre being impaired, that impairment is first felt and most felt at the greatest distance from that centre.

4. How is it to be acco nted for, that muscular palsy is more frequent than ancesthesia ?

" The r ason may be this : The office of the sentient nerves is probably an easier function than that of t e motor nerves.In some experiments which I made upon the mode and quickness of reparation of both classes of nerves after their division, I found that the sentient nerves resumed their functions in a shorter time than the voluntary nerves.I divided the facial branches of the se- venth and of he fifth nerves on one side in a cat: in the third week sensation had returned, but no sign of returning motion appeared till after the fourth.If this principle be true, it will solve the present question.The sentient nerves, it would appear, require a harder blow to palsy them than the voluntary.It de- serves besides to be pointed out, that, as the office of the former is to transmit towards the centre, not from the centre, it is natural to expect that they would be less susceptible of a force proceeding against the habitual course of these mo- tions.The connexion of the decussating fibres of the pyramid with the posterior part of the opposite half of the spinal cord, is likewise not quite as extensive as with the anterior."207.

It is certainly consistent with all that we know, to suppose that mere sen- sation is a phenomeno requiring less effort in the nervous system, than the propagation of the motor influence.Whether this is the whole or the greater part of the explanation of the phenomenon adverted to, is another matter.

Mr. Mayo concludes the section, by an allusion to the well-known rela- tionship between palsy and apoplexy.The one is, indeed, a greater degree of the other, or, rather, the producing lesions are so related.
ne other circumstance deserves notice.

It is the occurrence of convulsions on the same side as the cerebral lesion, concurrently with hemiplegia on the opposite.A case is related which is very interesting.

Case.W. Tucker, aetat.forty-two, brought into the Middlesex Hospital, and supposed to be intoxicated: he was drowsy, heavy, stupid, not insensi- ble, answered some questions ; the pulse small and slow.The left arm and leg powerless, face drawn to right side.When put to bed, he was seized with rigor, and complained of pain in the right side of occiput: in an hour afterwards the pulse rose, and the right side of the body became convulsed: v. s. oxviij: the convulsions ceased for a time, then returned with extreme violence, threatening to suffocate him: v. s. 3x1: the respiration became more free, but the convulsions remained : he then became comatose.He continued insensible during the night, the breat ing stertorous, right pupil dilated, left contracted, no pulse at the wrist: he died at 11, a.m.

A large cavity filled with blood, partly clotted, occupied the centre of the right hemisphere of the brain : it did not communicate with the lateral ven- tricle, but opene between the sulci of the convolutions, which for a large extent were lined with it; between their summits streaks of clotted blood lay, resembling veins.


1836]

Pathology of the Nervous System.


303

There was slight sanguineous effusion on the surface of the anterior lobe of the left hemisphere.

It is possible, says Mr. Mayo, but very unlikely, that this may have caused the convulsions of the right side of the body.It is unfortunate that even this degree of obscurity should hang over the case.We lately saw, with an intelligent surgeon, Mr. Skegg, of St. Martin's-place, an instance of hemi- plegia upon one side, and convulsions on the other.The patient was a young man, accustomed to drink hard, but of robust constitution.He was suddenly attacked with insensibility and stertor, and hemiplegia of the right side.Soon convulsions of the left side, which was sensible to stimulants, succeeded.No remedies exerted any influence on the symptoms, and, in about thirty-six hours from the commencement of the attack, the patient died.

On dissection, great softening of the left optic thalamus was discovered.

It formed in its centre a sort of bouillie, without any appreciable vascular injection around it.

We return to Dr. Hall.We left him at the commencement of our pur- suit of hemiplegia.We have agreed that that occurs on the side opposite to the one in which the cerebral lesion is found?on the same side as that in which the lesion of the oblong and spinal medulla is situated.He proceeds :?

" It has been further ascertained that, in experiments, lesions of the encephalon induce paralysis only, whilst lesions of the medulla oblongata and spinalis in- duce convulsion or paralysis, according to its severity.Hence it becomes an im- portant question to determine the cause of convulsive affections in disease of the encephalon." 34.

Dr. Hall attempts farther on to explain this point.It is well known to surgeons, that a small degree of pressure on the cerebrum will produce convulsion?a greater degree of pressure, paralysis.*If convulsions occur, * Mr. Mayo, in his remarks on apoplexy, goes still farther than this.He ob- serves, and we do not vouch for the correctness of the statement, but decidedl object to its positive character, that it is possible to distinguish when the effu- sion of blood is on the surface of the brain, because it is then uniformly attended "with convulsions.He quotes from Abercrombie the case of a man, a habitual sPirit-drinker, who, after drinking whiskey to excess, was found insensible, and bad attacks of violent convulsions at short intervals.He died soon after he was thus found, in an attack of the convulsions in question.

On removing th skull-cap after death, an appearance was observed on the surface of the dura mater, of coa ulated blood in small detached portions.? These appeared to have been discharged from small glandular-looking elevations ?n the outer surface of the dura mater, which were very vascular, and highly gorged with blood.There were depressions on the inner surface of the bone, which corresponded with these bod

s.On
raising the dura mater, there came mto view a coagulum of blood, covering and completely concealing the right hemisphere of the brain ; it was about two lines in thickness over the middle lobe, and became gradually thinner as it spread over the anterior and posterior lobes, and dipped down below the base of the brain.The coagulum being re- moved, measured about ?v.On the surface of the left hemisphere, the veins Were turgid with blood ; on the surface of the right, they were entirely empty ; bu the source of the hemorrhage could not be discovered.There was no fluid m the ventricles, and no other disease was discovered.

M E DI CO-C' H l KC7 RGIC A L liKYI KW.

[Oct. 1 as they occasionally do, after an injury of the head, that is resumptive evidence of moderate pressure.To us there appears no greater difficulty in acc unting-for convulsion from cerebral lesion, than in accounting for hemiplegia.If it is demonstrable, which it is, that a small quantity of blood effused upon the brain will g-ive rise to convulsion, it is not probable that, in experiments, lesions of the encephalon do produce paralysis only.What is the effusion of a little blood but an experiment ?It matters, we suppose, little, whether that be effected by an intentional or an unintentional blow from a bludgeon.The effect is the same in either case?a little blood is extravasated.If convulsion follows in the one instance, which it does, why should it not follow in the other, which Dr. Hall assures us it does not?

We would recommend him to re-consider this passage.But how is convulsion from cerebral disease or injury to be explained?Dr Hall offers the following solution, which, we must own, does not, to our appre- hension, do much more than express the actual fact." Disease of the meninges and of the brain, induces spasmodic actions.How is this explained?I think upon the principles of irritation and counter-pres- sure.

The first may act through the medium of the nerves distributed to the membranes,?as the recurrent of the fifth of Arnold.In reference to the se- cond, I may adduce several valuable facts.In an interesting case most anxi- ously watched, and accurately detailed to me, by my friend Mr. Toogood, of Bridgewater, of a little girl, aged thirteen months, the croup-like convulsion occurred repeatedly, until one day, when the bones of the cranium separated, the convulsion then ceased ; in a case of spina-bifida related to me by Mr. Herbert  Evans, of Hampstead, there was a croup-like convulsion whenever the little patient turned, so as to press upon the tumor.In the case of anencephalous foetus, described by Mr. Lawrence, convulsion was produced on pressing on the medulla oblongata.In a case of meningitis given by Dr. Abercrombie, the an- terior fontanelle became very prominent; pressure u on it induced convulsion.

Hypertrophy of the brain affords an argument of the same kind: it induces convulsion, except in the case in which the cranium grows with the encephalon.These and other facts lead me to think that convulsion arising from cerebral disease, is thus to be explained." 44.

The only explanation that we discern is contained in this sentence??

" upon the principle of irritation and counter-pressure."We may be ob- tuse, but really we conceive that explanation to amount to very little, and to leave a great deal to the genius of the reader.We repeat that there is no more difficulty in explaining the occurrence of convulsion than of hemi- plegia.The only apparent difficulty is in the inconsistency of the former, following dise se of the encephalon, and not experimental lesion?anin- consistency, which, for the reasons we have stated, we do not believe to be real.Unfortunately, however, the numerous experiments that have been made upon the brain have not dissipated the uncertainty that hangs over its precise functions.On the contrary, they have, in many instances, tended to render the obscurum obscurius, and, multiplying contradictory facts, have only thrown doubt on what was formerly deemed certain.That this is not an exaggerated view of the present state of the physiological pathology of the encephalon will be evident from the following passage." I must now," says Dr. Hall, " briefly state to you that, formerly, Sauce- rotte, in his Prize Memoir presented to the Academie Royal de Chirurgie, in 1768 ; and, more recently, MM.Foville and Pinel-Grandchamp, M. Serres, Lacrampe-Loustau, and M. Bouillaud, have attempted to shew, that, besides this crossed effect of the cerebrum, affections of the corpus striatum, or its middle lobe, induce paralysis of the inferior extremities ; whilst similar affections ?f the thalamus, or its posterior lobe, induce paralysis of the superior extremi- ties ; so that, if this opinion were true, there would be a doubly crossed effect.I use this phrase as a sort of mnemonic for you, if you should wish to speak of these opinions, for I fear I must call them by that name : M. Lallemand and ?M-Andral, after an examination of an extensive series of facts, have declared that the statement is without foundation.M. Bouillaud has further attempted to shew, that disease, or lesion, of the anterior lobe of the cerebrum leads to a loss of the pow r of articulation.But this opinion is equally contested by the two authors whom I have just quoted.

I must now briefly notice an attempt to localize the affections of the brain of a different kind, but equally disputed by these pathologists : MM.Delaye and, Foville have stated that the grey or cortical substance is principally affected in mania; MM.Bouchet and Cazauvieilh, whilst they agree with MM.Delaye and Foville in their view of the pathology of mania, contend that in epilepsy it is, on the contrary, the white or medullary portion of the brain which is diseased.

The tubercula quadrigemina alone have a crossed effect, both of convulsion, and paralysis.

M. Ollivier observes that a hsemorrhagy into the tuber annulare only para- lyzes the movements; M. Cruveilhier, on the contrary, asserts that such an affection destroys the sensations and the movements, but leaves the intellect un- injured.How many questions, then, still remain for future inquiry to solve!" 35.

How many indeed.Dr. Hall adds, what is pretty well known, that in those cases in which ha^morrhagv occupies an extensive space, affecting1 both hemispheres of the cerebrum,?as in meningeal haemorrhage at the summit, or at the base of the brain, in extensive hcEm rrhagy wit in the brain, extending1 from one hemisphere to the other, or into both ventricles,?generalparalysis is ob- served; the same event takes place in the cases in whic h a clot is formed ,n the mesial line in the tuber annulare.
We stride over many pages to notice other kinds of paralysis.Their con- nexion with the brain is less direct, or more obscure than that of the forms palsy we have quitted.To the practitioner and the physiologist they are interesting alike.

1-The first is Paralysis from Dental Irritation.Dr. Hall gives a case as a description.

Case.The child of Mr. Grant, an in elligent practitioner of Thayer Street, was twenty months old, and had been suffering for some time from dentition, being fretful, and having a cough during the night.On the morning of April 30th, 1835, her mother observed that she was incapable raising the right arm ; she retained the power of swinging the arm back- wards and forwards, and of bending the forearm on the arm, but had not the least power to raise the arm itself, as if the deltoid n^uscle only was para- lyzed.On examining t e arm, the child suffers no pain, and there is not the least reason to believe that any accident could have occasioned this loss ?f power.The general health of the child, with the exception above-men- tioned, is excellent; appetite good; bowels are every day relieved.

Dr. Marshall Hall, on seeing the child, recommended a gentle emetic, Mkoico-chirurgicAt.Review.

[Oct. 1 followed by a dose of castor oil; the gums over the four eye-teeth, which are all coming' forwards, to be carefully lanced every second day; and, ulti- mately, an embrocation to the arm; and a light unirritating diet.Thus the child went on with little alteration till the evening of May 6th, when she had several fits of coughing, resembling the convulsive crowing of croup.There was no fever, and nothing was done till next day, when the pain was removed from the back of the head, two leeches were applied behind the e r, and the other remedies were persevered with.On the 14th, the child had evidently regained some power in raising the arm, and there had been no return of the crowing cough.

On the 21st, one of the teeth had arrived at the surface, and the others were advancing.On the 10th of June, she had nearly recovered the com- plete power of her arm, and her night-cough was almost gone.The other teeth were not quite through the gum.The child got perfectly well.It is scarcely necessary to repeat that the treatment consisted in lancing the gums ?opening the bowels?andgiving light diet.

2. " We frequently observe," says Dr. Hall, " a liemiplegic paralysis from defective development of the opposite hemisphere of the cerebrum.In this case, both arm and leg, but chiefly the arm, are involved in the p ralysis.But it occasionally happens that one leg only is affected with a partial paralysis ; the limb does not grow as the other leg does, but remains thinner and shorter ; yet it does grow, so that the paralysis is not complete ; and it is moved, only with somewhat less powei than the other leg.

What is the nature of this partial paralysis ?Is it of dental origin ?Is it an affection of the spinal marrow, or of its nerves, equally partial ?Cases and careful examinations are entirely wanting to determine these questions." 84.Dr. Hall cites a very interesting case in the words of Dr. Webster, of Dulwich, the father of the child.

" When my boy," writes Dr. Webster, " was about twenty-months old, (he is now nine years,) he had a fit of illness, connected with dentition, which threat- ened the brain, and for which I opened the jugular vein and purged him.This took him off his feet; and, very soon after, he had a fall from a rather high cribbed; but this was not attended or followed by any apparent bad conse- quences.The child recovered his health; but, for some weeks, he seemed to have almost entirely lost the use of his legs, and, being uneasy about him, seve- ral of my medical friends saw him; amongst others, I think, yourself.He gradually, however, began to walk again, but not so steadily as before, as he tottered much in his steps, and was constantly falling over every little object that happened to be in hi3 way, and he had much less command over the left limb than the right.He seemed to walk on his toes.It was not at first ascer- tained that one leg was more affected than the other; but as he grew up and

Was breeched, the matter became more apparent; he plainly walked more firmly on the healthy limb, and less so on the lame one, and he threw it about more in walking and playing, and rarely set down the heel, except when walking slowly, never when running.He now runs on the toes of that foot, and with a sort of lurch; the limb is less firm the muscular power is evidently less, but the sen- sibility seems equal to the other.I have only to add, that the affected limb is about an inch shorter than the other, which is the reason of his walking on the toes." 85.

In juxta-position with this case is one taken from Dr.
bercrombie's work, which Dr. Hall may well style able.A very admirable and philosophical work?a treasure of facts to all who shall come after.We cannot refrain 1836] Pathology of the Nervous System.307 from introducingit, in order that our notice of this matter may be more complete.


"

It is now upwards of twenty years si ce I first saw a girl, aged, at that time, about eighteen months, and previously enjoying excellent health.She had been left for some time sitting upon damp grass, and was immediately seized with fever, accompanied by such a degree of oppression as led to an apprehen- sion of an affection of the brain.These symptoms, however, passed off in a few days, and, upon her recovery from them, it was found that she was entirely paralytic in the right lower extremity.She has, from that time, enjoyed unin- terrupted health, and is now a tall and strong young woman; but the right lower extremity has continued entirely paralytic.It is also a great deal smaller than the opposite extremity, and several inches shorter.All the joints are re- markably relaxed, and the muscles flaccid; but there is no other appearance of disease in any part of it, or in the spine." 85.Apoplexy.

From palsy we turn o apoplexy, two affections allied in cause, and com- monly co-existent in fact.We shall not, of course, give a history of apo- plexy, but merely select what has something in it to attract our special notice.

It is scarcely necessary for us to mention that from the slighter shades and symptoms of cerebral oppression up to what is familiarly called apoplexy, there is no natural resting place.The derivation of the term implies no more than suddenness of seizure, and a philosophical consideration of the disease does not tend to confine definition within narrow bounds.

Practically speaking, there is no point connected with apoplexy so im- portant, as recognizing the slighter forms or the pi-emonitory symptoms ?f it.Dr. Hall properly insists on this, and it is indeed of primary con- sequence.As we know that apoplexy is rather a disease of middle and ad- vanced than of early life, it is at the former periods that we watch most anxiously for those seemingly trivial indications of cerebral oppression, which to the well-informed medical man are so significant.

The morbid anatomy of apoplexy is far from affording such decisive data for diagnosis and treatment as might be wished, and, indeed, expected.We find?rupture of vessels and extravasation of blood?serous effusion into the ventricles or on the surface of the brain?congestion of its venous system, without rupture?andsoftening of the brain?andwe find nothing at all.Nor is severity of symptoms proportioned to extent of lesion.In many severe cases, the morbid appearances may be very slight, or there may be none?and i cases, in which the symptoms are not severe, the lesion may he most extensive.Mr. Mayo quotes from Dr. Abercrombie a case which exhibits the absence of any absolute ratio between organic alteration and sy ptoms, and we dwell on ore because, in practice, astonishment is frequently expressed by medical practitioners, when a state- ment of the sort is made.

Case.A

an, aged fifty-four, of a pletho
ic habit and short-necked, was admitted into the clinical ward of the Edinburgh Infirmary under the care ?fDr. Duncan on the 31st of May.He was in a state of nearly perfect coma, speechless, and with palsy of the right side to such an extent that [Oct. 1 even the intercostal mus les of that side did not act.The leg and arm of the left side were occasionally affected with convulsive motions.Breathing stertorous, deglutition much impaired, pulse 74.The affection was of three day ' standing, and had come on with vertigo, loss of vision, violent head- ach, and vomiting.The usual remedies were productive of no service.On the 1st of June there seemed to be a slight return of intelligence, but oma soon recurred, and the patient died on the 3rd.Dissection.No farther appearance f disease could be discovered, than that the choroid plexus seemed rather darker than usual, and the basilar artery was diseased at one spot.By the side of the artery, there was a spot of the cerebral substance, no larger than a barley-corn, which appeared somewhat softened, but even this Dr.Duncan considered as extremely doubtful.

Who would not have said that in such a case, at such an age, organic lesion would surely have been found ?

The evidence on which we conclude that pressure, generally from blood, is the essential cause of apoplexy, seems to be very clear and satisfactory.

That evidence commences, perhaps, with such a case as the one related by Zitzilius; where, a boy had drawn his neckcloth re arkably tight, and was whipping his top, stooping and rising alternately, when after a short time he fell down apoplectic.The neckcloth being unloosed, and blood being drawn from the jugular vein, he speedily recovered.Or perhaps it might start with the experiment of Sir Astley Cooper?who trephined a dog, and applied some pressure with his thumb upon the dura mater.The dog in- stantly became insensible, and had the symptoms of apoplexy.Sir Astley removed his thumb from the dura mater, and gradually the animal's sensibi- lity returned.This appears decisive, and from this experimental pressure up to the case of compression from depressed bone, or from effused blood, scarcely a link would seem wanting in the chain.Yet what point is there in medicine so settled, as not to foster doubt and admit of disputation ?It lias been, and it is a question with many, whether pressure is the essential physical cause of apoplexy.Mr. Mayo puts that question fairly:?

" The cases, which have been detailed, if t ey exemplify the features of apoplexy, exemplify no less the extreme difficulty of assigning their physical cause.

In cases of sanguineous, or serous effusion, it appears natural to consider the mechanical pressur as the cause of stupor.But the stupor is often slow in coming on, and often does not manifest itself till some time after the effusion has taken place; nor is it necessarily permanent, although the effusion remains : for it may be temporarily relieved by bleeding, or without any apparent cause gra- dually wears off.And, if it would not encumber this volume by too many illustrations, cases might be adduced, in which large extravasations of blood have existed without any degree of coma ; and still more numerous and striking cases of enormous accumulation of water in the heads of adults, without a single apoplectic symptom.The extrava ation> or pressure of effused fluid, where it exists in apoplexy, is probably therefore a part only of the physical cause of coma ; something there must be in addition, some change either in the condition of the nervous subst.ance,or in the cerebral circulation, that is brought on by, although, as in the first instance quoted, cap ble of existing independently of, any effusion, to constitute the immediate cause of the mental oppression.

definite relation to the organic lesion, when they flow from sudden extravasation of blood."187.

In order to set the operation of pressure in a proper point of view, it is necessary to attach due importance to two circumstances:?1.The sudden- ness of the compression?2.The possibility of pressure having existed during life, when no certain proof of it continues after death.

The evidence of pressure is positive.For, the thumb is laid on the dura mater?or t e bone is knocked in with a bludgeon?orblood is suddenly effused within the cranium, and instantly apoplexy follows.If those causes are removed, the apoplexy, in a fair case, where too much mischief has not been inflicted, is removed too.

Suddenness of compression is shewn by conclusive evidence to be an essential element in the production of decisive symptoms.No fact can be better made out, than the symptoms of pressure on certain parts of the spinal marrow, or on the medulla oblongata.Yet in cases where the com- pressing force has acted slowly, the most extraordinary lesions have been unattended with specific symptoms.

We are not to conclude, because we find no bl od effused, or no palpable congestion after death, that therefore no congestion has existed during life.The case of Zitzilius, the cases that every day present themselves, shew how fleeting cerebral congestion, attended with dangerous symptoms, may be.

Such pressure may have existed to a degre fatal to the performance of the Unctions of some brains, yet in death or fter death, when the circulation is s? modified, it may have ceased to be apparent.

The evidence against pressure is not positive.It chiefly resolves itself into the absence of the proof of pressure after death.But this, as we have observed, is inconclusive, for it can be shewn that pressure existed and did *njury, when after death, it has disappeared, and the laws of the cerebral circulation will explain many of those phenomena, which have been thought to tell against the theory of compression.No doubt cases may be picked out.where what must occasion pressure did not occasion apoplexy.But tl)ere is no instance in which the exception less destroys the rule, than this of the brain.There are no facts respecting it, decisive as they may seem, which have not striking exceptions.If any thing seems clear, it is that Sudden depression of a portion of the cranium will produce the symptoms of compression; but it is as clear that such depression has occurred and Persisted without occasioning such symptoms.It is hardly fair to say, that this disproves the operation of pressure, for it equally disproves the opera- tion of every thing.It not only tells against any theory of consequences, "ut it tells against the fact of consequences, which is an absurdity.The true inference from such cases is, that we are not sufficiently acquainted with all the conditions of the cerebrum, nor with the laws of its functions, to be able to appreciate the disturbing circumstances in a given case.On e whole, we think the arguments are in favour of the physical action cf compression constituting the most essential element, in the production cf what we call apoplexy.

. It might be expected that pressure about the cerebellum, or at all events, ln the vicinity of the medulla oblong ta, would be more rapidly fatal, than ?n the surface or in the substance of the cerebrum.


Much of the latter is

No. L.


Y

[Oct. 1 probably devoted to the performance of functions intellectual, rather than merely vital.The fact, at all events, is as we have stated.


Accidental Apoplectic Symptoms.

There are some symptoms -which may, perhaps, receive without much im- propriety this designation.Sometimes they are present?sometimesthey are not?and we know not, in many instances, why they should either exist or be absent.Practically speaking it is important to observe them.

Vertigo is such a symptom?Wepfer mentions the case of a woman, who was recovered after hanging-, by frequent bleeding; she was for some time afterwards affected with vertigo, which subsided gradually.

Vomiting is another symptom of this sort.Dr. James Johnson attended a female servant whose chief symptom was obstinate vomiting.He sent her to St. George's Hospital, where, after ineffectual treatment, she died.

No disease was discovered in the stomach, but an abscess existed in the cerebellum.

We were lately consulted on the case of a little boy who had been under the care of several eminent physicians.His chief symptom was vomiting, with a little pyrexia.We could discover no obvious lesion of the stomach.But the boy was of a lymphatic and strumous habit, and appeared rather heavy and drowsy.We determined to treat the case for a head affection, fearing there might be scrofulous tubercle in the cranium, or some organic mischief going on in it.We ordered repeated leeching's on the temples, succeeded by blisters behind the ears, and aperient medicines.In a few weeks the boy had quite recovered, although he had been previously leeched and blistered very liberally on the stomach to no purpose.

" The alliance between vertigo and sickness is remarkable.In injuries and diseases of the head, these feelings perpetuall accompany each other ; and there are curious instances which even go to show that the one has a necessary con- nection with the other.In persons sick at sea, it is very certain that the shifting motion of visible objects, and the instability and want of support felt, or, in other words, the disturbance of the sense of equilibrium, and the giddiness so produc d, are the causes of the sea sickness.If a person on ship-board, with feelings of nausea coming on, lie down and close his eyes, the nausea is won- derfully diminished ; yet the only difference which he has made, is excluding impressions wh ch favour the production of giddiness.When a person has drank immoderately of wine, on the contrary, if he shuts his eyes he experiences a strong vertig or sense of whirling, followed by nausea; but if, instead of giving way to this sensation, he fixes his sight on a stationary object near him, the vertigo is corrected by the steadiness of the visible object; and as the ver- tigo disappea s, the nausea wears off.The mitigation of the nausea is in both of these dissimilar instances the effect of getting rid of the vertigo." 194.Headache is another symptom of the kind that we have been speaking of.Headache has many causes.We allude only to one form of it, happening" under certain circumstances.Tissot for insta ce, so Mr. Mayo writes, mentions a woman, who, after complaining for some time of headache, was attacked with a great and sudden increase of pain, accompanied by loss o sleep, and died in a short time.On dissection no morbid appearance could be detected.A young woman, mentioned by the same writer, having, dur- ing the flow of the menses, suffered from a fright, the discharge stopped, and she became liable to frequent leipothymia.After suffering from this and various other symptoms for several months, she fell into a profound sleep, from which nothing could rouse her; this continued four days; she then came out of it and appeared to be recovering, when, after several days, she was seized with severe headache, anxiety, and convulsions, and died.No morbid appearance could be detected in any of the viscera.

We quite agree with Mr. Mayo that the pathology of such headache is analogous to that of simple apoplexy.The affections are all ed.There is no doubt that, exhaustion and extreme depletion will occasion headache.

We cannot wonder at that, when we recollect what the effect of both is on the heart.This becomes irritable, and acts with rapidity and violence.What blood there is, is driven with force through the org ns.We may pre- sume that the effect on the head is headache?weknow that in the arteries "^e have the bruit-de-soufflet, the indication of the extreme action excited by the heart.We remember the case of a man who had been furiously bled for hepatitis.He had violent headache, and throbbing in the cranium, and the bruit-de-soufflet was distinct in every artery of any size.He died and no lesion was found either in the head or heart.

In private practice we not unfrequently meet with such cases as the one we shall quote from Mr. May .They are often perplexing, and the more so because the cautious physician reflects that a little slip on his part may be disastrous in its consequences.On the whole it is better to lean to the side of depletion : an error on either side soon renders the case more ob- vious.But it is better that a man should be obviously weak, than that he should be obviously apoplectic." A gentleman," as our author tells us, " between his thirty-fifth and fortieth years, of a temperament inclining to nervous, but stout and muscular, habitually taking considerable exercise, and living heartily, and engaged in an active pro- fession, has experienced, on different occasions, when exhausted by days of pre- vious fatigue, the following attacks.After partaking early of a hearty breakfast, and travelling twenty miles, he was seized with vertigo, and inability to stand, and slight nausea: he took two glasses of brandy without any effect; but be- came relieved upon producing vomiting, by means of salt and water, and lying Perfectly still.On another occasion he awoke in the night, low, depressed, shivering violently, with a sense of failing power, like apparent dissolution ; this was relieved by applying hot bottles to the feet, and administering brandy.On another occasion, when exhausted by over-exertion, he was taken with a sense ?f feebleness joined to imperfect vision ; in which, at first, he could see only the ?bjects to which the optic axes were immediately directed; in half an hour afterw rds, this was changed to vision of the half of objects : with quiet and stimulants, in another half hour these sensations wore off.These seizures were followed by slight headach.He is now in perfect health; but feels on going through much excitement or exertion, that he might bring on a return of the eelings described."194.

We quit the consideration of apo lexy, to glance at almost similar patho- logical states?those of concussion and compression.It is impossible for any surgeon to understand or to treat either well, who is not familiarized with the phenomena of those affections of the brain which usually fall under the care of the physician.The latter would acquire an insufficient idea of the complaints he ministers to, were he not aware of the consequences of lnjuries of the cranium.Let us, then, glance at?Y 2 Medico-chirubgical Review.

[Oct. 1 Concussion and Compression.

1.The direct effects of concussion, or what is in common language called " concussion," are stated by Mr. Mayo to be, " syncope and something more."What the something more is, it is easier to imagine than to say, for, in truth, the exact definition of " coacussion" is difficult.In some surgical works in the hands of students, no such difficulty would appear to be experienced; the positive symptoms and precise diagnosis of " concussion" and " compression," are there laid down, and they even go so far as to determine the opposite condition of the pupil in each.

It is interesting to inquire, but difficult to ascertain, what is the alteration that the structure of the brain undergoes in concussion.The opportunities of examining the bodies of persons who die from simple concussion a e rare.It appears that it is, in some eases, impossible to distinguish any structural lesion?while, in others, laceration of the substance of the brain and ecchymosis may be found.Ecchymosis is only extravasation on a small scale, and, when it is present, the case trembles on the confines of concussion and compression.The symptoms of either are not separated by a broad and dis- tinct line of demarcation, but are insensibly blended and confounded.

The occasional consequences of concussion have attracted curiosity.The operations of the intellect are interfered with, and memory particularly suf- fers.Dupuytren relates the case of a person, who recollected only the syllables pa pa.This small stock of language was all that was left to him.

The cases published by Sir Astley Cooper and Sir B. Brodie are noto- rious.

Mr. Mayo points out the analogy between concussion and compression ; ?The instance, he says, in medical pathology to which it is most parallel, is the first stage of apoplexy from rupture of a vessel, which is characterized by paleness, feebleness of the pulse, and vomiting.In that case, in truth, the cause of the symptoms is equally mechanical?a blow from the gush of blood upon the brain.No doubt that, in each instance, the cerebrum re- ceives a shock.

2. Compression of the brain from mechanical causes, does not differ in symptoms from apoplexy with extravasation.The study of one elucidates, and is necessary for the appreciation of the other.Whether the compres- sion be from bone, or blood, or matter, does not signify, quoad the com- pression.But, in the latter case, inflammatory symptoms are associated with those of pressure, and may modify th m.The following is an interest- ing case of the effects of suppuration.

" A young man had a small portion of the left parietal bone denuded by a blow; it became necrosed, and was already beginning to loosen, when he ob- served that the thumb and fore-finger of the right hand were weak and numb : in a day or two he was taken with a slight epileptic seizure, which lasted four or five minutes : a similar fit recurred a few days afterwards.This I attributed to the confinement of matter between the bone and dura mater ; but as the bone was loosening, it as evident that there would shortly be a free escape for the matter ; 'so that I thought it better not to apply the trephine unless the symptoms became more urgent.As the ulcerated groove around the dead portion of bone enlar ed, the palsy of the thumb went away, the patient had no return of the epileptic seizure, the dead bone separated, and he recovered." 224.

Unfortunately, it seldom happens that when matter forms upon the dura 1836J Pathology of the Nervous System.

313 Water, after an injury of the head, an operation is sufficiently early to prevent extensive and fatal mischief.We have seen the skull trephined often when symptoms of suppuration in the cranium had occurred, but in no one in- stance has that operation been in such a case successful.On dissection, we usually discover that the suppuration on the surface of the dura mater is not limited to one spot, and frequently there is suppuration under the dura mater, and inflammatory softening1 of the brain in that situation.Yet a- vourable cases do now and then occur, to teach the surgeon not to abandon hope entirely.For instance :? Sophia Pennett, set.sixteen, was admitted into the Middlesex Hospital under the care of Mr. Joberns, on the 19th of October, 1815.She had been knocked down in the street by a carriage, the wheel of which had grazed the kft temple and denuded the parietal bone.She had lost a considerable quantity of blood from the temporal artery, as low and weak, and vomited.The part exposed did not recover : about a third of the surface of the parietal bone was necrosed.November 9th, having gone on favourably in the interval, but complaining occasionally of pain in the back of the head, she

Was taken with shivering and sickness.Nov. 10, she could not articulate: pulse 90, and irregular; at times insensible.12th, cannot put out her tongue : right side of the face and arm paralytic.Nov. 14th, Mr. Joberns trephined the parietal bone, when about a teaspoonful of ma ter escaped, which had been confined between the bone and dura mater : the latter was covered with a layer of organized lymph.The operation was performed about one o'clock ; it was followed by an immediate amendment.Nov. 15 : now quite sensible; her speech in great measure returned; she can move her arm.From this period her rec very was rapid.

A very fortunate case.

Blood may be effused under the dura mater.Cases have occurred, where,

?n trephining, the dura mater was raised and rendered blucish by blood be- eath it, and when the prominent membrane has been punctured, the blood has spirted out to the height of seven feet.Sir B. Brodie has put on record a ver remarkable fact of this description.

The follo ing is a short summary offered by Mr. Mayo, of the different effects of compression.

" 1 ?Coma without stertor : commonly resulting from extensive cerebral la- ceration and hemorrhage ; but sometimes from remediable extravasation.

2-Coma with stertor, and partial hemiplegia ; often resulting from depressed bone, or circumscribed extravasation, or suppuration, upon the dura mater.

3. Coma with violent convulsions; resulting from extravasation on the sur- ace of the brain, sometimes situated Avithout the dura mater. 4. Epileptic seizure ; from small circumscribed effusion [or depression of bone ?] upon the dura mater.

5. Acute pain in the head, from depression of bone. 6. Sudden and great decline of frequency in the pulse.This I witn ssed in a child, supervening several days after fracture of the skull.The symptom was ollowed in a few hours by coma and hemiplegia : there was extensive suppura- l0n between the bone and dura mater."228.

The catalogue is not quite complete, for other consequences from com- pression have been witnessed. 7. Delirium is a symptom that sometimes results from pressure on the.

hrain.We will relate a case which fell under our own care.

[Oct. 1

Case.A man was admitted into St.George's Hospital, after having fal- len on his head.

He was stunned for about ten minutes, but soon reco- vere his sensibility.Yet the sensibility was not perfect.When left to himself, he would continue talking in an incoherent way, and, when spoken to, said he would give us " a punch in the head."When asked if he had a wife, he replied?"Yes, too many."We should observe that th re was extensive ecchymosis in the frontal region, and particularly in the neighbourhood of the left eye.On the third or fourth day,* he was suddenly seized with what looked like delirium tremens, but the delirium soon assumed a very violent character, and it was necessary not only to put on a strait-waistcoat, but to secure him to the bed, and set powerful en to hold him down.

It was the most furious delirium we ever saw.What was curious, it was of an erotic character, and he used the most obscene language, and invited the nurse to go to bed with him.After this had continued for some hours, he gradually sank into the state of coma, with stertor, and died.

On dissection, it was found that the frontal bone was extensively fractured, the fracture running across the sethmoid, into the sella furcica, and both temporal fossae.Between the bone and the dura mater, opposite the anterior part of each cerebral hemisphere, was a large quantity of firm black coagulum.Opposite the cribriform plate of the cethmoid bone, the dura mater was lacerated, and the laceration extended into the substance of the brain, which contained about two drachms of bl od, and seemed slightly softened round it.

In this case, the symptoms were at first those of concussion.Afterwards they ce tainly were not the ordinary ones of compression.Yet there was an extensive fracture, with laceration of the dura mater and of the brain, blood on the former, and in the latter.From first to last there was a dis- positio to delirium.At first it was so slight as to be considered the result of intoxication?afterwards it was very furious, and lapsed into apoplectic in- sensibility.There was no appearance, however, in the lesion, of change corresponding to these great variations in symptoms.Could the slight sof- tening round the clot in the brain have modified the latter symptoms ?We see the same round apoplectic clots, without delirium.This case occurred six years ago, and we saw none similar to it until the year before last.A woman was then admitted into St.George's, after hav- ing received a blow upon the head.She was insensible at the time, but re- covered er consciousness in a great degree.On the second or third day she became delirious, furiously delirious.There was no heat of skin, the pulse was not accelerated, no symptom of inflammatory action was present.Recollecting the prece ing case, we expressed our suspicion of pressure from extravasated blood, there being no ev dence of fracture.In this opinion no one acquiesced.The woman died.On dissection, there was found exten- sive effusion of blood on the dura mater, beneath the left parietal bone, and no other lesion could be found.Delirium, then, must be received as an occasional effect of compression.

* We have full notes of this and of another similar case, but we cannot at this moment refer to them.


1886]

Pathology of the JVervous System 315

The only evidence of its cause during life, with which we are acquainted, is its sequence to an injury of the head, and its not beingaccompanied with he signs of inflammatory action.

8. In one case we saw extraordinary bulimia after an injury of the head, attended with all the symptoms of compression.The case was that of a boy.He would steal everything' eatable in the wards that he could procure.The bulimia gradually subsided.Perhaps this was only a post hoc.We men- tion the fact, but attach little importance to it. 9.Mr. Mayo makes no mention of perverted sensations and perverted in- tellectual operations, as a consequence of compression.He mentions only coma and hemiplegia.Yet we all know that, after compression, there have been instances in which particular senses have been altered.One patient always perceived a foul smell, and things that formerly gave a pleasant odour now 6eemed to emit a stench.Loss of memory, particularly in regard to special objects of it, has been noticed.We need not multiply examples of a fact which has been frequently noticed and r